drop symfony 4, allow symfony 7

Author: koertho

composer.json

@@ -9,9 +9,9 @@
     "heimrichhannot/contao-utils-bundle": "^3.0",
     "psr/container": "^1.0 || ^2.0",
     "spatie/schema-org": "^3.4",
-    "symfony/config": "^4.4 || ^5.4 || ^6.0",
-    "symfony/dependency-injection": "^4.4 || ^5.4 || ^6.0",
-    "symfony/http-kernel": "^4.4 || ^5.4 || ^6.0",
+    "symfony/config": "^5.4 || ^6.0 || ^7.0",
+    "symfony/dependency-injection": "^5.4 || ^6.0 || ^7.0",
+    "symfony/http-kernel": "^5.4 || ^6.0 || ^7.0",
     "symfony/service-contracts": "^1.0 || ^2.0 || ^3.0"
   },
   "autoload": {